1. Field of the Invention
The present invention relates to a method and a device for a arranging at least two sheets in a shingled mode of arrangement.
2. Description of Related Art
In the prior art methods and devices are already known, which are used for superimposing sheets discharged by a cutter in a 2-up mode of operation.
DE 34 33 497 A1 describes a device in which juxtaposed paper sheets are conducted into a merger having provided therein a conveying belt which extends transversely to a longitudinal axis of the device and by means of which one paper sheet is transported transversely to the longitudinal plane of the device and is thus slid on top of the other paper sheet.
DE 198 19 736 C1 discloses a device for superimposing paper sheets in which the paper sheets, which are initially arranged side by side, are slid one on top of the other via two planes by means of vacuum-type conveying belts, this being achieved in that the vacuum-type conveying belts are arranged at an oblique angle relative to the paper travelling direction.
U.S. Pat. No. 3,178,170 discloses a device for collecting individual sheets in which the sheets, which are provided in the device in juxtaposed relationship, are slid on top of one another by means of obliquely arranged transport rolls, the transport rolls being driven in common.
GB 2 083 448 A discloses a cutter and merger device by means of which a stack of superimposed sheets is produced from a plurality of single sheets.
GB 2 083 448 A discloses a cutter and merger device by means of which a stack of superimposed sheets is produced from a plurality of single sheets.
U.S. Pat. No. 4,674,375 relates to a merger in which three individual sheets, which were cut in a preceding section and which are present in parallel on the inlet of the machine, are merged into a stack in such a way that the individual sheets are arranged one on top of the other. The sheets are slid on top of one another and a stacking assembly by means of which the individual sheets are merged into a respective stack is provided only at the outlet of the device. The individual sheets are moved by transport rolls, which are driven in common.
One feature that is common to all the above-described systems, which are already known from the prior art, is that they only provide the possibility of superimposing at least two sheets which are supplied to such a device, the orientation of the superimposed sheets being in this connection always such that they form a stack in which the individual sheets are superimposed with all the edges flush.
In cases of use where e.g. the individual sheets were produced by respective cutting operations of cutters which are known per se, and are then merged into stacks by the above-described devices, and where further processing of these elements is then necessary, e.g. a grouping of individual documents, enveloping or the like, it will be necessary, not least in order to save space, to arrange the sheets in a shingled mode of arrangement, i.e. such that the sheets advanced are arranged one on top of the other with a small amount of longitudinal displacement, when the transport of the individual stacks is being continued. Related to predetermined dimensions, this will permit an increase in the transport capacity in comparison with the transport capacity in cases in which only individual sheets would be transported.
The above-described course of action, viz. sliding the individual sheets first on top of one another and depositing them in a stacked mode of arrangement and arranging them subsequently in a shingled mode of arrangement, necessitates, however, additional processing steps, since the individual sheets, which are discharged from the merger, are first collected in the form of a stack, whereupon each individual sheet must be drawn off from the stack formed, so as to accomplish the shingled mode of arrangement of these sheets; this necessitates additional operating steps and leads to a reduction of the operating speed, since e.g. during a clock cycle which is, for example, 200 ms long, only a single sheet can be drawn off, so that as much as 400 ms, i.e. two clock cycles of the operating cycle, are necessary for arranging two sheets in a shingled mode of arrangement.
DE 198 36 231 A1 refers to a device for transporting documents from at least two separate inlets to a common outlet; by means of this device a shingled mode of arrangement of the documents coming from the two separate inlets can be achieved at the common outlet. In particular, a first straight transport path is provided, which leads from one inlet to the common outlet, whereas a further transport path, which leads from the other inlet to the common outlet, extends at an oblique angle relative to the first transport path. In addition, the transport paths extend on different levels so that the lengths of the transport paths are different due to the fact that a transport path extends at an oblique angle and due to the different levels of the two transport paths. The speeds of the transport means along the transport paths can be adjusted independently of one another so that a shingled mode of arrangement, among other modes of arrangement, can be achieved at the common outlet.
It is the object of the present invention to provide a method and a device for arranging at least two sheets in a shingled mode of arrangement, which permit fast processing of sheets in a paper handling system and which reduce the number of clock cycles required.
The present invention is a method for arranging at least two sheets in a shingled mode of arrangement, the method comprising the steps of moving a first sheet of the at least two sheets in a paper travelling direction, and simultaneously moving a second sheet of the at least two sheets in a direction at an angle relative to the paper travelling direction in such a way that the at least two sheets are slid one on top of the other.
The present invention is a method for arranging at least two sheets in a shingled mode of arrangement, the method comprising the steps of moving a first sheet of the at least two sheets in a first direction at a first angle relative to a paper travelling direction, and a second sheet of the at least two sheets in a second direction at a second angle relative to a paper travelling direction in such a way that the at least two sheets are slid one on top of the other, the first and second angles being different.
The present invention is a method for arranging at least two sheets in a shingled mode of arrangement, the method comprising the steps of moving a first sheet of the at least two sheets in a first direction at a first angle relative to the paper travelling direction at a first speed, and a second sheet of the at least two sheets in a second direction at a second angle relative to the paper travelling direction at a second speed in such a way that the at least two sheets are slid one on top of the other, the first and second angles being identical, and the first and second speeds being different.
The present invention is a device for arranging at least two sheets in a shingled mode of arrangement, the device comprising a first transport means moving a first sheet of at least two sheets in a paper travelling direction, and a second transport means moving a second sheet of the at least two sheets in a direction at an angle relative to the paper travelling direction in such a way that the at least two sheets are slid one on top of the other.
The present invention is a device for arranging at least two sheets in a shingled mode of arrangement, the device comprising a first transport means moving a first sheet of the at least two sheets in a first direction at a first angle relative to a paper travelling direction, and a second transport means moving a second sheet of the at least two sheets in a second direction at a second angle relative to a paper travelling direction in such a way that the at least two sheets are slid one on top of the other, the first and second angles being different.
The present invention is a device for arranging at least two sheets in a shingled mode of arrangement, the device comprising a first transport means moving a first sheet of the at least two sheets in a first direction at a first angle relative to a paper travelling direction at a first speed, a second transport means moving a second sheet of the at least two sheets in a second direction at a second angle relative to a paper travelling direction at a second speed in such a way that the at least two sheets are slid one on top of the other, the first and second angles being identical, and the first and second speeds being different.
Due to the different movements of the individual sheets (different travelling distances and/or different speeds), the present invention succeeds in making a first sheet faster than a second one so that, when the sheets are being slid on top of one another, a displacement in the paper travelling direction is obtained, i.e. the individual sheets are arranged in a shingled mode of arrangement.
According to one embodiment of the present invention, the different speeds of the transport means accomplish a movement of the individual sheets in such a way that a first sheet is faster than a second sheet so that, when the sheets are being slid on top of one another, a displacement in the paper travelling direction is obtained, i.e. the individual sheets are arranged in a shingled mode of arrangement. The first speed v1 of the first sheet is preferably in the range of from 2 m/s to 5 m/s, and the second speed v2 of the second sheet is preferably in the range of from 1.05xc3x97v1 to 1.2xc3x97v1, i.e. it is 5% to 20% higher than v1. The displacement of the edges representing the leading edges in the paper travelling direction is preferably in the range of from 10 mm to 50 mm.
According to a further preferred embodiment, the method according to the present invention and the device according to the present invention are implemented such that the sheets are displaced by half their format width in a direction perpendicular to the paper travelling direction.
According to a further preferred embodiment of the device according to the present invention, the transport means in a transfer station are implemented as oblique transport means whose transport directions each extend at an acute angle towards a longitudinal centre plane.
According to a further preferred embodiment of the present invention, the transport means are defined by vacuum transport units which are arranged at an oblique angle relative to a paper travelling direction and between which a separating plate is arranged so that the conveying belts of the vacuum transport units cross.